Chapter 1

Question 1

Single Nucleotide Polymorphisms

Answer 1

variants at single nucleotide positions; one of the most common forms of DNA variation in human genome

Question 2

Copy Number Variations

Answer 2

form of genetic variation consisting of different numbers of large contiguous stretches of DNA from 1000 to millions of base pairs

Question 3

Epigenetics

Answer 3

heritable changes in gene expression that are not caused by alterations in DNA sequence

Question 4

Nucleosome

Answer 4

DNA segments of 147 base pairs wrapped around protein core (histone)

Question 5

Chromatin

Answer 5

DNA-histone complex linked by DNA linkers

Question 6

Heterochromatin

Answer 6

cytochemically dense and transcriptionally inactive

Question 7

Euchromatin

Answer 7

cytochemically dispersed and transcriptionally active

Question 8

Histone Methylation

Answer 8

lysines and arginines can be methylated; can be marked as activation or repression

Question 9

Histone Acetylation

Answer 9

lysine residues are acetylated by HAT to increase transcription

Question 10

Histone Phosphorylation

Answer 10

serine residues; opened up for transcription or inactivated

Question 11

DNA Methylation

Answer 11

high levels in gene regulatory elements; typically result in transcriptional silencing

Question 12

Chromatin Organizing Factors

Answer 12

bind to noncoding regions and control long-range looping of DNA

Question 13

miRNA

Answer 13

do not encode proteins; function to modulate the translation of target mRNAs into corresponding proteins

Question 14

Phosphatidylinositol

Answer 14

on inner membrane leaflet; can be phosphorylated to serve as scaffold for intracellular proteins; can be hydrolyzed by phospholipase C to generate intracellular signals

Question 15

Phosphatidylserine

Answer 15

normally restricted to inner face where is confers negative charge; when flipped to extracellular face, signals phagocytes to apoptosis

Question 16

Glycolipids and Sphingomyelin

Answer 16

preferentially expressed on extracellular face; important in cell-cell interaction

Question 17

MDR protein

Answer 17

multidurg resistant protein which pumps polar compounds out of cells and may render cancer cells resistant to treatment

Question 18

Epidermal Growth Factor (EGF)

Answer 18

Sources: activated macrophages, salivary glands, keratinocytes
Functions: mitogenic; stimulates keratinocyte migration; stimulates formation of granulation tissue

Question 19

TGF-a

Answer 19

stimulates proliferation of hepatocytes and other epithelial cells

Question 20

HGF

Answer 20

enhances proliferation of hepatocytes and other epithelial cells; increases cell motility

Question 21

VEGF

Answer 21

stimulates proliferation of endothelial cells; increases vascular permeability

Question 22

PDGF

Answer 22

chemotactic for neutrophils, macrophages, fibroblasts, and smooth muscle cells; activates and stimulates proliferation of fibroblasts, endothelial cells and other cells; ECM protein synthesis

Question 23

FGFs

Answer 23

chemotactic and mitogenic for fibroblasts; stimulates angiogenesis and ECM protein synthesis

Question 24

TGF-B

Answer 24

chemotactic for leukocytes and fibroblasts; stimulates ECM protein synthesis; suppresses acute inflammation

Question 25

Keratinocyte Growth Factor

Answer 25

stimulates keratinocyte migration, proliferation, and differentiation